Pigment identification of complex coating mixtures with sparkle color

ABSTRACT

A method that includes obtaining, using a processor, image data from a target coating. The method also includes performing, using the processor, an image analysis to determine at least one sparkle point from the image data, and performing, using the processor, a hue analysis to determine a sparkle color from the sparkle point. The method further includes calculating, using the processor, a sparkle color distribution, and generating, using the processor, a coating formulation that is the same or substantially similar in appearance to the target coating.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/121,869 filed Oct. 28, 2014, which is incorporated herein byreference.

FIELD OF THE INVENTION

In various embodiments, the present invention generally relates to amethod and apparatus for identifying physical property attributes ofcured complex coating (e.g., paint) mixtures.

BACKGROUND OF THE INVENTION

Due to the nature of complex mixtures within coatings, it is sometimesdifficult to formulate, identify, and/or search for acceptable matchingformulations and/or pigmentations. In an ideal setting, an individualcould view a complex coating mixture and determine the appropriatepigments within the coating mixture. However, in reality the pigments ina coating mixture may not be readily available in a set of toners of apaint system that is to be utilized to make a matching coating. Thus, askilled color matcher has to make a determination as to whether thepaint system contains appropriate offsets and, if so, must determineadditional changes which need to be made to accommodate the offsetsgiven that they are not identical matches to the original pigmentation.

A hypothetical solution to determining the composition of an unknownpigmentation is to read the unknown with a device that can search adatabase for the best matching coating formula within the database (or adevice that can immediately create a new coating formula). However, sucha solution is only hypothetical because systems are able to determinecolor or bulk effect pigment type, but generally cannot assist indetermination of, for example, the specific pearl necessary for acoating formulation match.

Traditional techniques to evaluate the properties of complex coatingmixtures include a variety of in plane viewing conditions (e.g., theJ361 Recommended Practice promulgated by SAE International) combinedwith microscopic evaluation of a sample. Such approaches are generallynot appropriately defined to address new effect pigmentations irecomplex mixtures and are largely focused on textiles and only“obscurely” identified “out-of-plane” viewing angles with at least twolight sources so that the effect pigmentations may be viewed properly.Other techniques involve using a spectrophotometer (e.g., in-planemulti-angle devices for effect samples and spherical devices forstraight shade samples). However, new pigments are not able to beadequately characterized using such techniques due to the uniqueproperties of Colorstream® pearls, colored aluminums, etc. For example,it may be challenging to view, for example, Colorstream® pigments and itmay be nearly impossible to see coarseness of colored aluminums and,thus, a microscope may be required to adequately determine specialeffect pigments, which is a time consuming process and may notsatisfactorily address application issues which modify thecharacteristics of the sample and the effect of the special pigments.

Other strategies have been developed using painted or virtual samplesrepresenting various textures, and then comparing those to unknownsamples. Such techniques often require substantial user intervention andare subjective, which produces inconsistent results depending on theskill of the user.

Thus, a need exists for systems and methods that are suitable foranalyzing complex coating mixtures having sparkle color.

SUMMARY OF THE INVENTION

In a first aspect, embodiments of the invention provide a method thatincludes obtaining, using a processor, image data from a target coating.The method also includes performing, using the processor, an imageanalysis to determine at least one sparkle point from the image data,and performing, using the processor, a hue analysis to determine asparkle color from the sparkle point. The method further includescalculating, using the processor, a sparkle color distribution, andgenerating, using the processor, a coating formulation that is the sameor substantially similar in appearance to the target coating.

In another aspect, embodiments of the invention are directed to a systemthat includes a database and a processor in communication with thedatabase. The processor is programmed to: obtain image data from atarget coating; perform an image analysis to determine at least onesparkle point from the image data; perform a hue analysis to determine asparkle color from the sparkle point; calculate a sparkle colordistribution; and generate a coating formulation that is the same orsubstantially similar in appearance to the target coating.

In another aspect, embodiments of the invention provide an apparatus.The apparatus includes means for obtaining image data from a targetcoating and means for performing an image analysis to determine at leastone sparkle point from the image data. The apparatus also includes meansfor performing a hue analysis to determine a sparkle color from thesparkle point and means for calculating a sparkle color distribution.The apparatus further includes means for generating a coatingformulation that is the same or substantially similar in appearance tothe target coating.

In a further aspect, embodiments of the invention provide anon-transitory computer readable medium including software for causing aprocessor to: obtain image data from a target coating; perform an imageanalysis to determine at least one sparkle point from the image data;perform a hue analysis to determine a sparkle color from the sparklepoint; calculate a sparkle color distribution; and generate a coatingformulation that is the same or substantially similar in appearance tothe target coating.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent of application file contains at least one drawing executed incolor. Copies of the patent or patent application publication with colordrawing(s) will be provided by the Office upon request and payment ofthe necessary fee.

FIG. 1 illustrates angles labeled according to standard mathematicalterminology.

FIG. 2 illustrates the angles of FIG. 1 labeled according to standardmulti-angle spectrophotometer terminology.

FIG. 3 illustrates angles with respect to a painted sample and lightinteraction with an effect flake.

FIG. 4 is an image of a special effect coated panel where a sample setof sparkle colors have been indicated with appropriately coloredcircles.

FIG. 5 is an image of the special effect coated panel of FIG. 4 at adifferent angle of observation.

FIG. 6 illustrates an embodiment of a process that calculates a formulafor a target complex coating.

FIG. 7 illustrates an embodiment of a system in which the processes ofembodiments of the present invention may be used.

DETAILED DESCRIPTION OF THE INVENTION

While the description herein generally refers to automotive andautomotive refinish paint, it should be understood that the devices,systems and methods apply to other types of coatings, including stainand industrial coatings. The described embodiments of the inventionshould not be considered as limiting. A method consistent with thepresent invention may be practiced in a variety of fields such as thematching and/or coordination of apparel and fashion products.

Embodiments of the invention may be used with or incorporated in acomputer system that may be a standalone unit or include one or moreremote terminals or devices in communication with a central computer viaa network such as, for example, the Internet or an intranet. As such,the computer or “processor” and related components described herein maybe a portion of a local computer system or a remote computer or anon-line system or combinations thereof. The database and softwaredescribed herein may be stored in computer internal memory or in anon-transitory computer readable medium.

Embodiments of the invention are directed generally to systems andmethods that use an image capturing device, such as a limitedmulti-angle color camera (optionally in combination with aspectrophotometer) that can produce improved and simplified results forpigment characterization and sample properties. Embodiments provide foran efficient method to determine the pigmentation (or an acceptableoffset) that reduces the number of database “hits” needed to matchsamples in a laboratory or field application. Further, embodimentsinclude methods to improve searching a database with the possibility toadjust to a better match such that a user is provided with the bestmatch possible and experiences reduced time and cost. Embodimentsprovide a solution that can quickly identify special effect pigments andgeneralize the ratios of those pigments, thus enabling faster and bettercolor matching while providing a color match that may be of higherquality.

Traditional spectrophotometers and visual viewing conditions considerthe angles and light sources represented in FIGS. 1 and 2. Both figurescontain the exact same angles, but FIG. 2 uses industry acceptedterminology to describe the angles in relation to the specular angle.The traditional mathematical standard is used herein. In variousembodiments, traditional light sources that use diffuse or collimatedcolor corrected light may be used and an image capturing device (e.g., acolor camera with appropriate resolution) may be used to collect imagesat one, some, or all of the identified or similar angles.

In various embodiments, the distribution of colored sparkles may bedetermined within a coating at a multitude of angles. Because micas andxirallics change colors uniquely over various viewing angles andconditions, the appropriate pearl may be selected for a search orformulation algorithm, and a relative ratio as to the amount of eachrequired to match the target coating may be estimated. Also, the sparklecolor may be used to assist in selection of, for example, appropriatealuminums and other special effect pigments such as glass flake becausethe color of such materials does not shift over various angles. Thus,embodiments may be used in determining, for example, ratios of aluminumsto pearls in effect coatings.

In various embodiments, a high pass filter may be applied to the targetimage to determine the brightest spots amongst the various pixels in theimage. The resultant data/image may include information on only thebright locations. The high pass filter may convolve a matrix of valueswith a high value center point and low value edge points with the matrixof intensity information of the image. This isolates high intensitypixels. To further refine the sparkle points, an edge detection methodof filtering may be applied in conjunction with the intensity filtering.

In various embodiments individual sparkle points may be labeled andcounted, thus isolating/labeling them based upon hue range. FIG. 4illustrates a simplified selection, limited to five different points forillustrative purposes, of hue based sparkle points and how the pointsmay be identified. For illustrative purposes only a small selection ofsparkle points have been identified by hue, but it can be seen thatthere are visibly at least one blue, one violet, one green, one red, andone orange sparkle colors that can be labeled. Regional labeling mayinclude a counter for each label segment. Embodiments of the regionallabeling methods described herein may include moving from pixel to pixelfrom left to right, top to bottom of the image, finding pixels that havenot yet been labeled that match a specific quality, and labeling nearbypixels that have that met the same criteria up to a certain number ofmovements from the first labeled pixel. A second pass of regionallabeling may be used to connect regions adjoining regions that meet thesame criteria. Such two-fold regional labeling may be implementedthrough multiple passes, one each for the assigned hue ranges, or as onepass with checks for specific hue range values.

The techniques described herein may result in a count of labeled sparklepoints, each meeting criteria based upon the individual hue criteria,which can then be formatted and output as desired.

Embodiments may include the use of a series of hue-based band passfilters that identify individual hue regions independent of lightnessand/or brightness. Regional labeling and analysis of chroma andlightness (and/or brightness) of the regions may be used to isolateindividual sparkle points within each hue band. Such a technique maydetermine sparkle points while estimating the percentage of the imagethat falls within each hue to enable a relatively quick analysis ofcolor change in sparkle color over multiple images to supplement anyfurther identification. In various embodiments, a hand stop filler maybe used in place of or in combination with a band pass filter.

In various embodiments, the image data is used to create a matrix of thesame size with two to three indices in its third dimension. The pixelimage data may only contain RGB values. In such a case, it may benecessary to determine information on intensity (for ease ofmanipulation), hue, and labeling in the matrix. Also, in variousembodiments utilization of images at multiple angles may be convolvedwith a filter and the differences may be mapped between two (andlabeled/counted) to identify aluminum, micas, and special effects as theintensities and/or colors change between the angles.

Similar sparkle points themselves, based on hue with or withoutchromaticity, may each be averaged into a single color point; thuseffectively providing a distribution of sparkle colors for the measuredarea (i.e., five blue sparkles, five red sparkles, resulting in 50% bluesparkles and 50% red sparkles of all of the sparkles counted for thegiven area). The distribution may be used to determine the relativeamount of a given toner within the complex coating (i.e., a fractionalamount correlated to the overall effect contribution). The sparkle colormay further be compared back to a database of sparkle color for, forexample, masstones and/or binary mixtures of paint systemtoners/pigments. The comparison may be used to select the most similartoners available in a given paint system to be used for effect matching.Also, the toner selection pool and relative amount of each toner may beused to feed a formulation or search engine. In various embodiments, theinformation may be placed into decision points for a Bayesian system toproduce particle identification, formulation, match searching, and/oradjusting.

It can be understood that embodiments of the invention may be used inconjunction with other texture parameters (e.g., intensity) and/orreflectance data.

In various embodiments, in order to properly identify the type oftoners, or an offset thereof, used in an unknown or target sample, it isdesirable to observe the correct angles and compare back to existingknown toners in a database that has been previously created. Binarymixtures of toners may be generated to evaluate the impact of variousconcentrations of the toners on their sparkle color attribute.

Each hue within the distribution of the sparkle color to the database oftoners may be compared at each selected angle. For example, all tonershaving a specific red hue at a given angle may be compared to theunknown sample. Evaluation of the sparkle color over the range of theangles selected may be compared between the unknown and the toners. Thetoners within the database displaying the most similar sparkle colorover all evaluated angles are those which are best utilized to match theunknown sample. An example of the differences which may be identifiedvia using various embodiments is shown in comparison of FIGS. 4 and 5.The circled points in the two images reveal that the sparkle spotschange in both hue and intensity at different angles. In variousembodiments, this situation becomes more complex with a combination ofpearl and aluminum toners only to the extent that the ratio of sparklesthat it may be desirable to manage change color over the range ofangles. For example, an unknown sample may have 50% silver sparkles and50% green sparkles at a given angle and 100% silver sparkles and 0%green sparkles at another angle. This is indicative of aluminum andgreen pearl toners present within a coating, where the pearlcontribution to the sparkle color was minimized at one angle due to theunique properties of the pearl. This information may provide a targetratio of the mixture (i.e., a 50/50 blend of the total sparklecontribution at one angle).

FIG. 6 illustrates an embodiment of a process that calculates a formulafor a target complex coating. Embodiments of the present invention maybe used to search a database where the sparkle color attribute of eachsample within the database is known. As illustrated in FIG. 6, aftermeasuring the unknown with, for example, a measurement device such as acolor camera enhanced spectrophotometer at step 10, image analysis, asdescribed hereinabove, may be used to determine the sparkle points of aselected angular image at step 12. Once the sparkle points have beendetermined, a hue analysis may be used at step 14 to determine sparklecolor which, in turn, may be used to average similar sparkle points, asdescribed hereinabove, to produce a sparkle color distribution at step16. A search against a database of complex mixtures may be performed atstep 20 to result in the determination of the best special effect matchwithin the database. This can be accomplished by comparing the sparklecolor distribution at each angle evaluated between the unknown and thedatabase at step 22. The database match having the closest alignment tothe unknown at all evaluated angles is the best match within thedatabase at step 24. In various embodiments, the importance of an angleor set of angles may be weighted to skew the results returned from thesearch to adjust for market preference.

Once the best match is found within a database, an adjustment to thematch may be made if desired as indicated at step 26. In variousembodiments, an adjustment may be made with addition of identifiedtoners (steps 28 and 30) or an adjustment based solely using the tonerswithin the selected match (step 32). An adjustment based solely usingthe toners within the selected match in various embodiments requires theadditional step of having identified toners within the unknown sampleand comparing them to the existing list of toners within the bestidentified match. The best identified matching toners can be determinedat step 34 in a similar fashion to the previously described searching ofthe database for a best match, but the comparison may differ inrequiring the inspection of a toner database rather than a database ofpreformulated matches at step 36. Some or all of the toners which arenot already included in the best match may be considered for addition tothe formulation during an adjustment at step 38. Whether or not step 38is performed, the ratios of the toners may be adjusted to most closelyalign with the actual sparkle color attribute at each angle at steps 40and 42. In various embodiments, the adjustment may be accomplished byunderstanding the color sparkle values of each toner at variousreduction levels based upon masstones and mixtures within the database.A correlation can be derived (e.g., linear, polynomial, etc.) for eachtoner within the database which indicates the contribution to sparklecolor distribution based on concentration. The correlation may then beused to adjust the amount of individual toners to best match the sparklecolor distribution within the unknown at all considered angles. Onceeither the match or toner search is completed the best matching options44, 46 may be returned to the user performing the search.

In various embodiments specific sparkles may be “mapped” at variousangles so that the sparkle color of a given sparkle may be tracedthroughout each angle considered. In such an embodiment a more specificidentification of a toner may be made because the exact changes (or lackthereof) at each angle may be identified and compared to a database ofknown toners. Such embodiments may eliminate the potential for amisinterpretation of the characteristics of each sparkle at a givenangle compared to a “bulk” distribution assessment method where anindividual sparkle may be assumed to change color from green to violet,when in fact the individual sparkle does not make this change betweenangles. However, the end result of the search, adjustment, and/orformulation will not change significantly by mapping individual sparklecolors because if the overall distribution of the sparkle color is metat each angle the match to the unknown will be acceptable.

Embodiments may include the simplification of the problem to match anunknown first by identification of the bulk toners, such as “mica,”“aluminum,” or “xirallic.” This may be beneficial to simplify anidentification and/or search by limiting it to a smaller selection fromthe database for comparison. In various embodiments it is not necessaryto identify the exact toner used in the coating, but rather a suitableselection of toners is satisfactory to address the color and textureissues. Once the toner type has been generally determined, the tonersmay be more specifically characterized and compared to a database forselection from a plurality of toners.

FIG. 7 illustrates an embodiment of a system 90 which may be used toidentify physical property attributes of a coating mixture of a targetsample. A user 92 may utilize a user interface 94, such as a graphicaluser interface, to operate a spectrophotometer and/or a camera 96 tomeasure the properties of a target sample 98. The data from thespectrophotometer and/or a camera 96 may be transferred to a computer100, such as a personal computer, a mobile device, or any type ofprocessor. The computer 100 may be in communication, via a network 102,with a server 104. The network 102 may be any type of network, such asthe Internet, a local area network, an intranet, or a wireless network.The server 104 is in communication with a database 106 that may storethe data and information that is used by the methods of embodiments ofthe present invention for comparison purposes. In various embodimentsthe database 106 may be utilized in, for example, a client serverenvironment or in, for example, a web based environment such as a cloudcomputing environment. Various steps of the methods of embodiments ofthe present invention may be performed by the computer 100 and/or theserver 106.

In another aspect, the invention may be implemented as a non-transitorycomputer readable medium containing software for causing a computer orcomputer system to perform the method described above. The software caninclude various modules that are used to enable a processor and a userinterface to perform the methods described herein.

It will be readily appreciated by those skilled in the art thatmodifications may be made to the invention without departing from theconcepts disclosed in the forgoing description. Accordingly, theparticular embodiments described in detail herein are illustrative onlyand are not limiting to the scope of the invention.

What is claimed is:
 1. A computer implemented method, comprising:obtaining, using an image capturing device, multiple images eachobtained at a different angle with respect to a surface of a targetcoating; performing, using an electronic computer processor in operativeassociation with at least one filtering technique, an image analysis onthe obtained images to determine at least one sparkle point within theimages; performing, using the processor, a hue analysis to determine asparkle color from the sparkle point; calculating, using the processor,a sparkle color distribution in response to the determined sparklecolor; and generating, using the processor, a coating formulation thatis the same or substantially similar in appearance to the targetcoating.
 2. The method of claim 1, further comprising mapping at leastone difference between multiple selected images at different angles inresponse to a change in intensity between the selected images.
 3. Themethod of claim 1, further comprising mapping at least one differencebetween multiple selected images at different angles in response to achange in color between the selected images.
 4. The method of claim 1,further comprising deriving a correlation for at least one toner whereinthe correlation indicates a contribution of the toner to the sparklecolor distribution.
 5. The method of claim 4, further comprising usingthe derived correlation at multiple angles to match at least one tonerto the sparkle color distribution.
 6. The method of claim 1, furthercomprising mapping a selected sparkle point at different selected anglesby tracing a sparkle color associated with the sparkle point throughoutthe different angles.
 7. The method of claim 1, wherein generating thecoating formulation comprises generating a list of toners.
 8. The methodof claim 1, wherein generating the coating formulation comprisescomparing the sparkle color distribution to a plurality of known coatingformulations.
 9. A system comprising: a database; and a processorprogrammed for communication with the database, the processor programmedfor: obtaining multiple images each at a different angle with respect toa surface of a target coating, performing, in operative association withat least one filtering technique, an image analysis on the obtainedimages to determine at least one sparkle point within the images,performing a hue analysis to determine a sparkle color from the sparklepoint, calculating a sparkle color distribution in response to thedetermined sparkle color, and generating a coating formulation that isthe same or substantially similar in appearance to the target coating.10. The system of claim 9, further comprising the processor programmedfor mapping at least one difference between multiple selected images atdifferent angles in response to a change in intensity between theselected images.
 11. The system of claim 9, further comprising theprocessor programmed for mapping at least one difference betweenmultiple selected images at different angles in response to a change incolor between the selected images.
 12. The system of claim 9, furthercomprising the processor programmed for deriving a correlation for atleast one toner wherein the correlation indicates a contribution of thetoner to the sparkle color distribution.
 13. The system of claim 12,further comprising the processor programmed for using the derivedcorrelation at multiple angles to match at least one toner to thesparkle color distribution.
 14. The system of claim 9, furthercomprising the processor programmed for mapping a selected sparkle pointat different selected angles by tracing a sparkle color associated withthe sparkle point throughout the different angles.
 15. The system ofclaim 9, wherein generating the coating formulation comprises generatinga list of toners.
 16. The system of claim 9, wherein generating thecoating formulation comprises comparing the sparkle color distributionto a plurality of known coating formulations.
 17. A non-transitorycomputer readable medium comprising software for causing a processor to:obtain multiple images each at a different angle with respect to asurface of a target coating; perform, in operative association with atleast one filtering technique, an image analysis on the obtained imagesto determine at least one sparkle point within the images; perform a hueanalysis to determine a sparkle color from the sparkle point; calculatea sparkle color distribution in response to the determined sparklecolor; and generate a coating formulation that is the same orsubstantially similar in appearance to the target coating.